TW202414905A - Antenna module - Google Patents

Abstract

Provided is an antenna module. The antenna module includes a plurality of conductive layers stacked in a first direction, the antenna module including a first patch antenna including at least one radiator provided in at least one conductive layer, and an electromagnetic band gap (EBG) structure including a plurality of pillars spaced apart from the at least one radiator in a direction perpendicular to the first direction, the plurality of pillars surrounding the at least one radiator, wherein each of the plurality of pillars includes two or more plates provided parallel with each other in two or more conductive layers, respectively, and at least one via connecting the two or more plates. The antenna module may have characteristics of improved performance and high utilization.

Description

Antenna Module

Exemplary embodiments of the present invention relate to wireless communications, and more particularly to wideband antennas and antenna modules including wideband antennas. [CROSS-REFERENCE TO RELATED APPLICATIONS]

This application claims priority to Korean Patent Application No. 10-2019-0068268 filed on June 10, 2019 with the Korean Intellectual Property Office, the entire text of which is incorporated herein by reference.

To increase the throughput of wireless communications, high frequency bands may be used. For example, wireless communication systems such as 5G specify the use of millimeter wave (mmWave) frequency bands. Therefore, antennas used for wireless communications may be required to provide wide bandwidth. In addition, antenna arrays including multiple antennas may be used for beamforming, and antenna arrays may be required to provide good beam coverage. However, in the case of portable wireless communication devices (such as mobile phones), the space for antennas may be limited, and therefore, antennas that provide good performance despite the limited space and the presence of other components in close proximity may be required.

One or more exemplary embodiments provide a broadband antenna that provides improved performance and high utilization even in a limited space, and an antenna module including the broadband antenna.

According to one aspect of an exemplary embodiment, an antenna module is provided, comprising a plurality of conductive layers stacked in a first direction, the antenna module comprising: a first block antenna, comprising at least one radiator disposed in at least one conductive layer; and an electromagnetic band gap (EBG) structure, comprising a plurality of pillars spaced apart from the at least one radiator in a direction perpendicular to the first direction, the plurality of pillars surrounding the at least one radiator, wherein each of the plurality of pillars comprises two or more plates disposed parallel to each other in two or more conductive layers, and at least one through hole connecting the plates.

According to another aspect of the exemplary embodiment, an antenna module is provided, comprising a plurality of conductive layers stacked in a first direction, the antenna module comprising an endfire antenna, the endfire antenna comprising a first pattern and a second pattern having shapes symmetrical to each other, the first pattern and the second pattern being configured to receive differential signals from feed lines adjacent to each other in the second direction, wherein the first pattern and the second pattern are respectively disposed in different conductive layers and respectively include overlapping portions in the first direction.

According to another aspect of the exemplary embodiment, an antenna module is provided, comprising a plurality of conductive layers stacked in a first direction, the antenna module comprising: a molded portion comprising a first region and a second region adjacent to each other in a second direction perpendicular to the first direction, the molded portion comprising an epoxy molding compound (EMC); a first block antenna comprising at least one radiator disposed in at least one conductive layer above the first region; and an end-fire antenna comprising a first pattern and a second pattern having shapes symmetrical to each other, the end-fire antenna being disposed above the second region, and the first pattern and the second pattern being configured to receive differential signals.

According to another aspect of an exemplary embodiment, a design method of an antenna module including a block antenna is provided, the design method including: determining a spacing of a plurality of posts included in an electromagnetic bandgap (EBG) structure surrounding a radiator of the block antenna based on an impedance of the block antenna; and determining the number and size of panels included in each of the plurality of posts parallel to each other based on the impedance of the block antenna.

In this specification, the Z-axis direction may be referred to as the first direction, which is the direction in which multiple conductive layers are stacked, and an element arranged in the +Z direction relative to other elements may be referred to as being located on or above other elements, and an element arranged in the -Z direction relative to other elements may be referred to as being located below or below other elements. The Y-axis direction and the X-axis direction may be referred to as the second direction and the third direction, respectively, a plane formed by the X-axis and the Y-axis may be referred to as a horizontal plane, and a plane perpendicular to the X-axis or the Y-axis may be referred to as a side surface of the element. Unless otherwise specified in this specification, the area of an element may be referred to as the size occupied by the element in a plane parallel to the horizontal plane, and for ease of explanation, only some layers may be described in the drawings in this specification.

FIG1 is a perspective view of an antenna module 10 according to an exemplary embodiment. As shown in FIG1 , the antenna module 10 may include a block antenna 11, a ground plane 12, and an electromagnetic band gap (EBG) structure 13, and may include a plurality of conductive layers. The antenna module 10 may be an antenna or a block antenna, and may also be a single element of an antenna array.

The antenna module 10 can output and receive signals for wireless communication. For example, the antenna module 10 can be included in a wireless communication device, which is included in a wireless communication system. The wireless communication system can include, for example, a wireless communication system using a cellular network such as a 5th generation (5G) wireless system, a Long Term Evolution (LTE), an LTE-Advanced system, a code division multiple access (CDMA) system, and a Global System for Mobile Communications (GSM) system, a wireless local area network (WLAN) system, or any other wireless communication system. In the following, the wireless communication system is mainly described with reference to a wireless communication system using a cellular network, but the exemplary embodiments are not limited thereto.

In an exemplary embodiment, the antenna module 10 may be included in a user equipment (UE) as a wireless communication device included in a wireless communication system. The UE may be stationary or mobile, and may be any device capable of communicating with a base station to send and receive data and/or control information. For example, the UE may include a terminal, a terminal device, a mobile station (MS), a mobile terminal (MT), a user terminal (UT), a subscriber station (SS), a wireless device, a handheld device, etc.

To increase throughput, wireless communications may use high frequency bands. For example, the 3rd Generation Partnership Project (3GPP) may propose a millimeter wave (mmWave) band greater than 24 GHz in new radio (NR). For such high frequency bands, an antenna module 10 may be required to provide broadband, but the space for the antenna module 10 in a UE such as a mobile phone may be limited, and due to the miniaturization of the UE, the space for the antenna module 10 may be further reduced. In addition, the impact of peripheral components on the antenna module 10 may increase. As described below with reference to the accompanying drawings, an antenna module according to an exemplary embodiment may have a reduced size while providing broadband, and therefore may be included in a UE (such as a mobile phone). In addition, since the size can be adjusted, the desired performance of the antenna can be more easily obtained, and the performance of a wireless communication device including the antenna can be improved by using a material that provides relatively good characteristics.

1 , a block antenna 11 may include at least one radiator above a ground plane 12. The radiator may be formed in a conductive layer and may include, for example, metal. When the block antenna 11 includes two or more radiators parallel to each other, a feed may be connected to the bottommost radiator (e.g., 11_3 in FIG. 3 ) and coupling between the radiators may occur. The radiator may have a circular shape, as shown in FIG. 1 , or may have any shape, such as a rectangular shape. Exemplary embodiments are described primarily with reference to a block antenna 11 including three circular radiators parallel to each other, but the embodiments are not limited thereto.

The EBG structure may be a structure that generates a stop band that blocks electromagnetic waves in a specific frequency band by forming a small metal pattern periodically arranged on a dielectric substrate. The EBG structure 13 in FIG. 1 may include a plurality of columns that surround the block antenna 11 in a direction perpendicular to the Z-axis direction, and the plurality of columns may be configured to receive a ground potential. For example, as shown in FIG. 1 , the EBG structure 13 may include a column 13_1 connected to a ground plane 12, and a plurality of columns each having the same structure as the column 13_1 may be arranged on the ground plane 12 surrounding the block antenna 11 in the X-axis direction and the Y-axis direction. However, the embodiment is not limited thereto, and a different number of columns than the plurality of columns shown in FIG. 1 may surround the block antenna 11.

1, two or more plates parallel to each other may be periodically arranged in the EBG structure 13. For example, the column 13_1 may include four plates parallel to each other respectively formed in four conductive layers, and the four plates parallel to each other may be periodically arranged through a plurality of columns in the X-axis direction and the Y-axis direction. In an exemplary embodiment, each of the plates included in the column 13_1 may be formed in a conductive layer different from a conductive layer in which a radiator of the block antenna 11 is formed. The EBG structure 13 may improve impedance matching in a target frequency band by increasing a ground potential, and may improve impedance in multiple frequency bands by adjusting the spacing between a plurality of columns and the size of the plates. In addition, if the EBG structure 13 is included in an antenna array in which a plurality of block antennas are arranged, the characteristics of the antenna array can be improved by removing surface waves that may occur in microstrip antennas. An example of a column included in the EBG structure 13 is described below with reference to FIG. 4A and FIG. 4B.

2A and 2B are plan views of examples of antenna modules 10a and 10b according to an exemplary embodiment. The plan views of FIG. 2A and FIG. 2B respectively show EBG structures 13a and 13b, each including a plate of a different shape. As described above with reference to FIG. 1, the EBG structures 13a and 13b in FIG. 2A and FIG. 2B may respectively surround the block antenna 11a and the block antenna 11b in a direction perpendicular to the Z-axis direction, and may respectively include a plurality of columns.

2A , the antenna module 10a may include a block antenna 11a, a ground plane 12a, and an EBG structure 13a. The block antenna 11a may include a first radiator 11_1a and a second radiator 11_2a located above the ground plane 12a, and may further include a third radiator (e.g., 11_3 in FIG. 3 ) between the second radiator 11_2a and the ground plane 12a. In an exemplary embodiment, the first radiator 11_1a at the uppermost position, the second radiator 11_2a at the middle position, and the third radiator at the bottommost position may have areas that decrease in the order of the second radiator 11_2a, the third radiator, and the first radiator 11_1a. In an exemplary embodiment, the block antenna 11a may be connected to two feeds for dual-polarization. For example, as shown in FIG. 2A , the block antenna 11a may be connected to feeds at a first feed point FP1 and a second feed point FP2, respectively. The third radiator at the bottommost position may be connected to through holes included in the feeds at the first feed point FP1 and at the second feed point FP2, wherein the first feed point FP1 is spaced apart from the center of the third radiator in the X-axis direction, and the second feed point FP2 is spaced apart from the center of the third radiator in the -Y-axis direction.

The EBG structure 13a may include a plurality of columns including rectangular plates, as shown by the dotted lines in FIG2A. For example, as shown in FIG2A, the column 13_1a may include a square plate, and as described above with reference to FIG1, may also include at least one rectangular plate parallel to the plate shown in FIG2A. Hereinafter, exemplary embodiments are described with reference to a plurality of columns including rectangular plates, such as the EBG structure 13a in FIG2A, but the embodiments are not limited thereto.

Referring to FIG2B , the antenna module 10b may include a block antenna 11b, a ground plane 12b, and an EBG structure 13b. The block antenna 11b may include a first radiator 11_1b and a second radiator 11_2b above the ground plane 12b, and may also include a third radiator (e.g., 11_3 in FIG3 ) between the second radiator 11_2b and the ground plane 12b. The block antenna 11b may be connected to the feeds at the first feed point FP1 and the second feed point FP2 for dual polarization. The EBG structure 13b may include a plurality of posts, the posts including circular plates, as shown by the dotted lines in FIG2B . For example, as shown in FIG. 2B , the column 13_1b may include a circular plate, and as described above with reference to FIG. 1 , may also include at least one circular plate parallel to the plate shown in FIG. 2B .

Fig. 3 is a side view of the antenna module 10 according to an exemplary embodiment. The side view of Fig. 3 shows the antenna module 10 of Fig. 1 in a direction parallel to the X-axis direction. Hereinafter, the description given with reference to Fig. 3 that overlaps with the description given with reference to Fig. 1 is omitted.

3, the antenna module 10 may include a block antenna 11, a ground plane 12, and an EBG structure 13. The block antenna 11 may include a first radiator 11_1, a second radiator 11_2, and a third radiator 11_3. The third radiator 11_3 may be connected to a first through hole V31 and a second through hole V32 each included in a feed line. The EBG structure 13 may include a plurality of columns. Each of the plurality of columns may include four plates parallel to each other, and may include through holes that interconnect the plates. In an exemplary embodiment, the plurality of columns may be connected to the ground plane 12.

The antenna module 10 may include a plurality of conductive layers. For example, as shown in FIG. 3 , the antenna module 10 may include a first conductive layer L1 to an eighth conductive layer L8 arranged in sequence. Each of the first conductive layer L1 to the eighth conductive layer L8 may include a pattern including a conductive material such as metal. For example, as shown in FIG. 3 , the first radiator 11_1 may be formed in the first conductive layer L1, the second radiator 11_2 may be formed in the sixth conductive layer L6, and the third radiator 11_3 may be formed in the seventh conductive layer L7. In addition, the ground plane 12 may be formed in the eighth conductive layer L8. In an exemplary embodiment, a dielectric material may be disposed between each of the first conductive layer L1 to the eighth conductive layer L8.

The column included in the EBG structure 13 may include a plate formed in a conductive layer different from the conductive layer in which the first radiator 11_1, the second radiator 11_2, and the third radiator 11_3 of the block antenna 11 are formed. For example, as shown in FIG3 , the column of the EBG structure 13 may include plates respectively formed in the second conductive layer L2, the third conductive layer L3, the fourth conductive layer L4, and the fifth conductive layer L5, which are layers different from the first conductive layer L1, the sixth conductive layer L6, and the seventh conductive layer L7 in which the first radiator 11_1, the second radiator 11_2, and the third radiator 11_3 are formed. Examples of columns are described below with reference to FIGS. 4A and 4B , which show an example of region A of FIG. 3 including two adjacent columns.

In an exemplary embodiment, the antenna module 10 may be manufactured by a printed circuit board (PCB) process. In the PCB process, when a pattern included in a conductive layer does not exist or is insufficient, a corresponding conductive layer may not be easily formed, and due to the corresponding conductive layer, a final structure different from the designed structure may be formed. Therefore, additional operations may be required to prevent or reduce this undesirable phenomenon. According to an exemplary embodiment, as shown in FIG. 3, a plate included in a column of an EBG structure may be formed in a conductive layer of radiators 11_1, radiators 11_2, and radiators 11_3 in which a block antenna 11 is not formed, and therefore, the antenna module may be manufactured more easily, and therefore, the cost and time for manufacturing the antenna module 10 may be reduced.

However, the exemplary embodiment is not limited to the structure shown in Fig. 3. For example, in the exemplary embodiment, the block antenna 11 may include less than or more than three radiators parallel to each other, and the radiators may be formed in a conductive layer different from the conductive layer shown in Fig. 3. In addition, in the exemplary embodiment, the EBG structure 13 may include a column including less than or more than four plates, and the plates may be formed in a conductive layer different from the conductive layer shown in Fig. 3.

Fig. 4A and Fig. 4B are side views of a column according to an exemplary embodiment. The side views of Fig. 4A and Fig. 4B show an example of region A of Fig. 3 containing two adjacent columns.

4A and 4B, the first radiator 11_1, the second radiator 11_2, and the third radiator 11_3 may be formed in the first conductive layer L1, the sixth conductive layer L6, and the seventh conductive layer L7, respectively, and the ground plane 12 may be formed in the eighth conductive layer L8. In an exemplary embodiment, the distance between the first conductive layer L1 to the seventh conductive layer L7 may be constant to a first distance H1, and the second distance H2 between the seventh conductive layer L7 and the eighth conductive layer L8 may be greater than the first distance H1.

4A , a first column PI1a having the same structure as a second column PI2a may be adjacent to a second column PI2a at a first spacing P1. In the present invention, the spacing may be referred to as the distance between the centers of adjacent elements. The first column PI1a may include a first plate PL1a, a second plate PL2a, a third plate PL3a, and a fourth plate PL4a, which are formed in a second conductive layer L2, a third conductive layer L3, a fourth conductive layer L4, and a fifth conductive layer L5, respectively. As described above with reference to FIGS. 2A and 2B , each of the first plate PL1a to the fourth plate PL4a may have any shape in an XY plane or a horizontal plane. In addition, the first column PI1a may include a first through hole V1a connecting the first plate PL1a to the second plate PL2a, a second through hole V2a connecting the second plate PL2a to the third plate PL3a, and a third through hole V3a connecting the third plate PL3a to the fourth plate PL4a, and may include a fourth through hole V4a connecting the fourth plate PL4a to the ground plane 12 to provide a ground potential to the first plate PL1a to the fourth plate PL4a. In an exemplary embodiment, the fourth through hole V4a may connect the fourth plate PL4a to the ground plane 12. In an exemplary embodiment, the fourth through hole V4a passing through the sixth conductive layer L6 and the seventh conductive layer L7 may be a through hole.

As described above with reference to Fig. 1, the EBG structure including the first column PI1a and the second column PI2a can provide different advantages. In addition, the first spacing P1 between the first column PI1a and the second column PI2a, the width W of the first plate PL1a to the fourth plate PL4a in the Y-axis direction (or its length in the Y-axis direction) and/or the first distance H1 between adjacent plates can be determined according to the required impedance of the block antenna when designing the antenna.

Referring to FIG. 4B , a first column PI1b having the same structure as the second column PI2b may be adjacent to the second column PI2b at a first spacing P1. The first column PI1b may include a first plate PL1b, a second plate PL2b, a third plate PL3b, and a fourth plate PL4b, and may include a first through hole V1b, a second through hole V2b, and a third through hole V3b for connecting the plates adjacent to each other among the first plate PL1b, the second plate PL2b, the third plate PL3b, and the fourth plate PL4b. Different from the first column PI1a in FIG. 4A , the first column PI1b in FIG. 4B may further include a first through hole pad VP1 formed in the sixth conductive layer L6 and a second through hole pad VP2 formed in the seventh conductive layer L7. Therefore, the first column PI1b may include a fourth through hole V4b connecting the fourth plate PL4b to the first through hole pad VP1, and may also include a fifth through hole V5b connecting the first through hole pad VP1 to the second through hole pad VP2 and a sixth through hole V6b connecting the second through hole pad VP2 to the ground plane 12 to provide a ground potential to the second through hole pad VP2. In an exemplary embodiment, the sixth through hole V6b may connect the second through hole pad VP2 to the ground plane 12. Similar to the plate, the first through hole pad VP1 and the second through hole pad VP2 may have any shape located in the XY plane or the horizontal plane and may have, for example, a circular shape or a rectangular shape.

Fig. 5 is a graph showing characteristics of an antenna module according to an exemplary embodiment. The graph of Fig. 5 shows S-parameters of an antenna module including an EBG structure and an antenna module omitting the EBG structure in a millimeter wave band.

The antenna module omitting the EBG structure may have a relatively high S-parameter under different conditions, as shown by the dashed line and the double dashed line in FIG5 , while the antenna module including the EBG structure may have a relatively low S-parameter under corresponding different conditions, as shown by the thin solid line and the thick solid line in FIG5 . In this way, the antenna module including the EBG structure may have a more stable radiation pattern and gain.

Fig. 6 is a plan view of an antenna module 60 according to an exemplary embodiment. The plan view of Fig. 6 shows the antenna module 60, which includes a block antenna 61 and an end-fire antenna 64 adjacent to one side of the block antenna 61. Similar to the antenna module 10 of Fig. 1, the antenna module 60 of Fig. 6 may include a block antenna 61, a ground plane 62, and an EBG structure 63 in a block antenna portion PA. In addition, the antenna module 60 may include an end-fire antenna 64 in an end-fire antenna portion EA, which is adjacent to the block antenna portion PA in the +Y axis direction.

Due to the strong straightness of high frequency signals such as millimeter waves, the antenna module 60 may include an end-fire antenna 64 and a block antenna 61 to improve beam coverage. The end-fire antenna 64 may include a dipole antenna, and the dipole antenna may generally have a length corresponding to half the wavelength (λ), such as the length in the X-axis direction in FIG. 6 . However, as described above with reference to FIG. 1 , the available space of the antenna module 60 may be limited, and therefore, a wide bandwidth and a relatively good radiation pattern may need to be used within the limited space.

6 , the end-fire antenna 64 may include a first pattern 64_1 and a second pattern 64_2. The first pattern 64_1 and the second pattern 64_2 may be configured to receive a differential signal from a feed in the -Y axis direction, and may be referred to as a first radiator and a second radiator, respectively. As shown in FIG6 , the first pattern 64_1 and the second pattern 64_2 may have shapes symmetrical to each other, and the first pattern 64_1 may be formed in a conductive layer below a conductive layer in which the second pattern 64_2 is formed. Unlike a dipole antenna structure including patterns arranged in the same conductive layer, the first pattern 64_1 and the second pattern 64_2 of the end-fire antenna 64 may be formed in different conductive layers, respectively. In addition, as shown in FIG6 , the first pattern 64_1 and the second pattern 64_2 may at least partially overlap in the Z axis direction. Therefore, the end-fire antenna 64 can use the coupling between the first pattern 64_1 and the second pattern 64_2, and the coupling coefficient can be more easily adjusted by adjusting the overlap distance between the first pattern 64_1 and the second pattern 64_2. Therefore, the end-fire antenna 64 can have a length in the X-axis direction shorter than 1/2 of the wavelength (λ), for example, a length in the X-axis direction shorter than 1/4 of the wavelength (λ).

In an exemplary embodiment, the end-fire antenna 64 may have a bow-tie shape. For example, as shown in FIG. 6 , each of the first pattern 64_1 and the second pattern 64_2 may have a shape in which the length in the Y-axis direction increases as the distance from the overlapping portion in the Z-axis direction increases. Due to this bow-tie shape, the bandwidth and impedance matching characteristics of the end-fire antenna 64 may be improved. An example of the end-fire antenna 64 is described with reference to FIGS. 8 and 10 .

In an exemplary embodiment, the antenna module 60 may include a through hole wall 65 including a plurality of through holes configured to receive a ground potential for promoting a reflection effect of the end-fire antenna 64. For example, as shown in FIG6 , the antenna module 60 may include a through hole wall 65 including a plurality of through holes (e.g., V60, etc.) aligned in the X-axis direction between the end-fire antenna 64 and the EBG structure 63. Due to the ground wall formed by the through hole wall 65, a relatively good radiation pattern may be generated from the end-fire antenna 64. The through hole wall 65 may include through holes spaced apart from each other in the X-axis direction as shown in FIG6 , may include through holes that touch each other in the X-axis direction, or may include through holes forming through hole pads that touch each other in the X-axis direction.

Fig. 7 is a side view of an antenna module 60 according to an exemplary embodiment. The side view of Fig. 7 shows the antenna module 60 of Fig. 6 in a direction parallel to the X-axis direction.

7 , the antenna module 60 may include a block antenna 61, a ground plane 62, and an EBG structure 63 in the block antenna portion PA. In addition, the antenna module 60 may also include a first additional ground plane 62' and a second additional ground plane 62", which are formed in the ninth conductive layer L9 and the tenth conductive layer L10, respectively. A through hole wall 65 may be disposed between the ground plane 62 and the second additional ground plane 62", and may include a plurality of through holes arranged in the X-axis direction. For example, as shown in FIG. 7 , the through-hole wall 65 may include through-holes aligned in the Z-axis direction, i.e., a first through-hole V61 connecting the ground plane 62 to the first additional ground plane 62′ and a second through-hole V62 connecting the first additional ground plane 62′ to the second additional ground plane 62″. In an exemplary embodiment, the through-hole wall 65 may include a through-hole passing through the first additional ground plane 62′. In addition, the height of the through-hole wall 65 (i.e., its length in the Z-axis direction) is not limited to the height shown in FIG. 7 , and in an exemplary embodiment, the through-hole wall 65 may extend beyond the ground plane 62.

The antenna module 60 may include a first pattern 64_1 formed in the ninth conductive layer L9 and a second pattern 64_2 formed in the eighth conductive layer L8 in the end-fire antenna portion EA. As described above with reference to FIG. 6 , the first pattern 64_1 and the second pattern 64_2 may be formed in different conductive layers, respectively, and may at least partially overlap in the Z-axis direction, and thus, coupling between the first pattern 64_1 and the second pattern 64_2 may be used. In an exemplary embodiment, the first pattern 64_1 and the second pattern 64_2 may be formed in conductive layers different from the conductive layer L9 and/or the conductive layer L8, respectively, and may be formed in conductive layers that are not adjacent to each other based on a coupling coefficient.

FIG8 is a plan view of a pattern of an end-fire antenna 64 according to an exemplary embodiment, and FIG9A and FIG9B are graphs showing characteristics of an antenna module according to an exemplary embodiment. The plan view of FIG8 shows a pattern 80 as an example of the first pattern 64_1 included in the end-fire antenna 64 in FIG6, and the second pattern 64_2 shown in FIG6 may have a shape symmetrical to the shape of the pattern 80 shown in FIG8 about the Y axis. In addition, the graphs in FIG9A and FIG9B show S-parameters of the end-fire antenna 64 including the pattern 80 of FIG8 and a pattern having a shape symmetrical to the pattern 80 in the millimeter wave band. Hereinafter, FIG8, FIG9A, and FIG9B are described with reference to FIG6.

8 , as described above with reference to FIG. 6 , the end-fire antenna 64 may have a bow-tie shape. As shown in FIG. 8 , the pattern 80 may include a leaf portion LEAF and a stem portion STEM. The stem portion STEM may extend in the Y-axis direction and may include a first end 81 for receiving a differential signal and a second end 82 connected to the leaf portion LEAF. The leaf portion LEAF may be connected to the second end 82 of the stem portion STEM and may have a shape extending in the Y-axis direction away from the second end 82 of the stem portion STEM. The leaf portion LEAF may have a first length LEN1 in the Y-axis direction and a second length LEN2 in the X-axis direction. As described below, the first length LEN1 and the second length LEN2 may be determined based on the desired main frequency of the end-fire antenna 64. In the present invention, the first length LEN1 may be the width of the leaf portion LEAF, and the second length LEN2 may be the length of the leaf portion LEAF.

9A , when the overlap distance between the two patterns is constant, the main frequency of the end-fire antenna 64 can be changed according to the first length LEN1. Similarly, referring to FIG. 9B , when the overlap distance between the two patterns is constant, the main frequency of the end-fire antenna 64 can be changed according to the second length LEN2. Therefore, the first length LEN1 and the second length LEN2 of the pattern 80 can be determined based on the desired main frequency.

FIG10 is a plan view of an end-fire antenna 100 according to an exemplary embodiment, and FIG11 is a graph showing characteristics of an antenna module according to an exemplary embodiment. The plan view of FIG10 shows the end-fire antenna 100, which includes a first pattern 100_1 having the same shape as the pattern 80 of FIG8 and a second pattern 100_2 having a shape symmetrical to the pattern 80 of FIG8. In addition, the graph in FIG11 shows the S-parameter of the end-fire antenna 100 of FIG10 according to the overlap distance D in the millimeter wave band.

10 , as described above with reference to FIGS. 9A and 9B , the main frequency may vary according to the size of the first pattern 100_1 and the second pattern 100_2. As described above with reference to FIG. 6 , the bandwidth, gain, and/or main frequency of the end-fire antenna 100 may vary according to the degree of overlap between the first pattern 100_1 and the second pattern 100_2. For example, as shown in FIG. 10 , an overlap distance D may be defined, which indicates the distance at which the leaf portion LEAF of the first pattern 100_1 and the leaf portion LEAF of the second pattern 100_2 overlap in the X-axis direction, and the bandwidth, gain, and/or main frequency of the end-fire antenna 100 may depend on the overlap distance D.

11 , while maintaining the shapes of the first pattern 100_1 and the second pattern 100_2 , the bandwidth, gain, and main frequency of the endfire antenna 100 may vary according to the overlap distance D. Therefore, the overlap distance D of the endfire antenna 100 may be determined based on the required bandwidth, gain, and/or main frequency.

FIG12 is a plan view of an antenna module 120 according to an exemplary embodiment, and FIG13A, FIG13B, and FIG13C are graphs showing characteristics of the antenna module 120 according to an exemplary embodiment. The plan view of FIG12 shows the antenna module 120 including a 1×4 antenna array. In addition, the graphs of FIG13A, FIG13B, and FIG13C show radiation patterns of the antenna module 120 of FIG12 according to the spacing of the single element.

12, the antenna module 120 may include a first single element 121, a second single element 122, a third single element 123, and a fourth single element 124 spaced apart from each other according to a second spacing P2. In an exemplary embodiment, each of the first single element 121, the second single element 122, the third single element 123, and the fourth single element 124 may have a structure that is the same as or similar to the antenna module 60 of FIG6. The antenna module 120 may include a through-hole wall similar to the through-hole wall 65 of FIG6, to which a ground potential is applied between the end-fire antennas EA1 to EA4 and the EBG structure 125.

Each of the first single element 121, the second single element 122, the third single element 123, and the fourth single element 124 of the antenna module 120 may include a first block antenna PA1, a second block antenna PA2, a third block antenna PA3, and a fourth block antenna PA4 in the block antenna portion PA and include an EBG structure 125. The first block antenna PA1 to the fourth block antenna PA4 may be spaced apart from each other in the X-axis direction according to the second spacing P2. The EBG structure 125 may include a plurality of columns, and the plurality of columns may surround the first block antenna PA1 to the fourth block antenna PA4 while spacing the first block antenna PA1 to the fourth block antenna PA4 from each other in a direction perpendicular to the Z-axis direction. In an exemplary embodiment, block antennas adjacent to each other may share a plurality of posts arranged between the block antennas adjacent to each other. For example, as shown in FIG. 12 , a plurality of posts G1 aligned in the Y-axis direction between the first block antenna PA1 and the second block antenna PA2 may be arranged like a plurality of posts G2 spaced apart from the first block antenna PA1 in the −X-axis direction and aligned in the Y-axis direction. Therefore, the phenomenon that the ground potential between the block antennas becomes greater than the ground potential at the edge of the antenna array can be reduced or prevented, and therefore, the first block antenna PA1 and the fourth block antenna PA4 respectively included in the single element are arranged to be adjacent to the edge of the antenna module 120, that is, the first single element 121 and the fourth single element 124 can have the same environment as the second block antenna PA2 and the third block antenna PA3 respectively included in the second single element 122 and the third single element 123.

The antenna module 120 may include a first end-fire antenna EA1, a second end-fire antenna EA2, a third end-fire antenna EA3, and a fourth end-fire antenna EA4 in the end-fire antenna portion EA, which is adjacent to the block antenna portion PA in the +Y axis direction. The first end-fire antenna EA1 to the fourth end-fire antenna EA4 may be spaced apart from each other in the X axis direction according to a second spacing P2.

13A, 13B, and 13C, the gain and half power beam width (HPBW) of the antenna module 120 may vary according to the second spacing P2 of the single elements. FIG. 13A shows a radiation pattern corresponding to the minimum second spacing P2, FIG. 13B shows a radiation pattern corresponding to the middle second spacing P2, and FIG. 13C shows a radiation pattern corresponding to the maximum second spacing P2. As the second spacing P2 increases, the angle of the HPBW on the Z-Y plane covered by the first end-fire antenna EA1 to the fourth end-fire antenna EA4 may be maintained, while the angle of the HPBW on the X-Y plane, i.e., on the plane where beamforming is formed, decreases and the side lobe increases. Therefore, the second spacing P2 may be determined to compensate for the insufficient resolution of the phase shifter corresponding to the first single element 121 to the fourth single element 124. In addition, the antenna module 120 can have characteristics similar to those when the corresponding elements are omitted, even when it includes elements (such as feeders, radio frequency integrated circuits (RFICs), etc.) that can be arranged under the first block antenna PA1 to the fourth block antenna PA4 and the first end-fire antenna EA1 to the fourth end-fire antenna EA4.

Fig. 14 is a perspective view of an antenna module 140 according to an exemplary embodiment. The perspective view of Fig. 14 shows the antenna module 140, which includes an antenna array corresponding to the plan view of Fig. 12 and a molded portion MO disposed below the antenna array.

As shown in FIG. 14 , the antenna module 140 may include a block antenna portion PA and an end-fire antenna portion EA adjacent to each other in the Y-axis direction and a molded portion MO located below the block antenna portion PA and the end-fire antenna portion EA in the Z-axis direction. The antenna module 140 may include RFIC, passive components, etc. located on the bottom surfaces of the block antenna portion PA and the end-fire antenna portion EA. The molded portion MO may include an epoxy molding compound (EMC) material to improve the mounting reliability and heat dissipation characteristics of the RFIC and the passive components. The molded portion MO may affect the characteristics of the end-fire antenna included in the end-fire antenna portion EA. For example, when the dielectric constant of the dielectric surrounding the end-fire antenna in the end-fire antenna portion EA is higher than the dielectric constant of the EMC material, the active S-parameter of the end-fire antenna and the aiming direction of the radiation pattern may change. Hereinafter, an example of an antenna module 140 designed in consideration of the EMC material of the molded portion MO is described below with reference to FIGS. 15A and 15B .

15A and 15B are side views of an example of an antenna module 140 according to an exemplary embodiment. The side views of FIG15A and FIG15B show an example of the antenna module 140 of FIG14 in a direction parallel to the X-axis direction.

15A , the antenna module 150a may include a block antenna portion PA' and an end-fire antenna portion EA' adjacent to each other in the Y-axis direction, and may include a molded portion MO' located below the block antenna portion PA' and the end-fire antenna portion EA'. The molded portion MO' may include a first region R1 located below the block antenna portion PA' and a second region R2 located below the end-fire antenna portion EA'. In an exemplary embodiment, the EMC material constituting the molded portion MO' may have a dielectric constant that matches the dielectric constant of a dielectric surrounding the end-fire antenna in the end-fire antenna portion EA'. Therefore, the second thickness T2a (i.e., the length of the second region R2 in the Z-axis direction) may match the first thickness T1a of the first region R1.

15B , the antenna module 150b may include a block antenna portion PA" and an end-fire antenna portion EA" adjacent to each other in the Y-axis direction, and may include a molded portion MO" located below the block antenna portion PA" and the end-fire antenna portion EA". The molded portion MO" may include a first region R1 located below the block antenna portion PA" and a second region R2 located below the end-fire antenna portion EA". In an exemplary embodiment, the EMC material constituting the molded portion MO" may have a dielectric constant that matches the dielectric constant of a dielectric surrounding the end-fire antenna in the end-fire antenna portion EA". Therefore, the second thickness T2b (i.e., the length of the second region R2 in the Z-axis direction) may be smaller than the first thickness T1b of the first region R1. In this way, when the molded portion MO" has a reduced thickness below the end-fire antenna portion EA", an EMC material with a high dielectric constant can be used, and due to the advantages provided by the EMC material, the performance of the antenna module 150b can be further improved.

FIG16 is a flow chart of a design method for an antenna according to an exemplary embodiment. The design method S100 of the antenna in FIG16 may be a design method for an antenna module, and may represent a design method for an antenna module, the antenna module including an antenna array, such as the antenna module 140 in FIG14. As shown in FIG16, the design method S100 of the antenna may include a plurality of operations S120, S140, and S160, and each of the plurality of operations S120, S140, and S160 may be executed again based on the results of executing other operations. In an exemplary embodiment, the antenna design method S100 of Figure 16 can be executed by a computing system that includes a non-volatile memory medium storing at least one processor and software containing a series of instructions executed by the at least one processor, and the computing system can generate data containing geometric information about the designed antenna module.

According to the design method of the antenna of the exemplary embodiment, operation S120 of designing a block antenna may be performed. For example, the number, size, arrangement, etc. of radiators included in the block antenna may be determined, and the structure of multiple columns included in the EBG structure surrounding the block antenna may be determined. An example of operation S120 is described below with reference to FIG. 17. Operation S140 of designing an end-fire antenna may be performed. For example, the size of the patterns symmetrical in shape to each other included in the end-fire antenna, the spacing distance in the Z-axis direction, the overlapping distance in the X-axis direction, etc. may be determined. An example of operation S140 is described below with reference to FIG. 18. Operation S160 of designing an antenna array may be performed. For example, the spacing of single elements, the size of the molded portion, etc. may be determined. An example of operation S160 is described below with reference to FIG. 19 .

FIG17 is a flow chart of a design method of an antenna according to an exemplary embodiment. The flow chart of FIG17 shows an example of operation S120 in FIG16, and as described above with reference to FIG16, operation S120' of designing a block antenna may be performed. Operation S120' may include operation S122 and operation S124, and in an exemplary embodiment, each of operation S122 and operation S124 may be performed again based on the result of performing another operation.

Operation S122 of determining the distance between the posts based on the target impedance D120 of the block antenna may be performed. As described above with reference to the accompanying drawings, the EBG structure may improve the impedance matching of the block antenna. The EBG structure may include a plurality of posts, and the distance between the posts may be determined based on the target impedance D120 of the block antenna.

An operation S124 of determining the number and spacing of the panels based on the target impedance D120 of the block antenna may be performed. The column included in the EBG structure may include two or more panels parallel to each other, and the panels may be respectively formed in a conductive layer of a radiator in which the block antenna is not formed. Depending on the number and size of the panels, the impedance of the block antenna may vary, and therefore, the number and size of the panels may be determined based on the target impedance D120 of the block antenna.

FIG18 is a flow chart of a design method of an antenna according to an exemplary embodiment. The flow chart of FIG18 shows an example of operation S140 in FIG16, and as described above with reference to FIG16, operation S140' of designing an end-fire antenna may be performed. Operation S140' may include operation S142 and operation S144, and in an exemplary embodiment, each of operation S142 and operation S144 may be performed again based on the result of performing another operation. Hereinafter, FIG18 is described with reference to FIG10.

Operation S142 of determining the size of the first pattern 100_1 and the second pattern 100_2 may be performed based on the target main frequency D142 of the endfire antenna 100. As described above with reference to FIGS. 9A and 9B , the main frequency may vary according to the size of the leaf portion LEAF of the first pattern 100_1 and the second pattern 100_2. Therefore, the length and width of the leaf portion LEAF of the first pattern 100_1 and the second pattern 100_2 may be determined based on the target main frequency D142 of the endfire antenna 100.

Operation S144 of determining the overlap distance D of the first pattern 100_1 and the second pattern 100_2 may be performed based on the target main frequency D142 and the target bandwidth and/or gain D144 of the endfire antenna 100. As described above with reference to FIGS. 10 and 11 , the main frequency D142, the bandwidth, and the gain D144 of the endfire antenna 100 may vary according to the overlap distance D of the first pattern 100_1 and the second pattern 100_2. Therefore, the overlap distance D may be determined based on the target main frequency D142, the target bandwidth, and/or the gain D144 of the endfire antenna 100.

FIG19 is a flow chart of a design method of an antenna according to an exemplary embodiment. The flow chart of FIG19 shows an example of operation S160 in FIG16, and as described above with reference to FIG16, operation S160' of designing an antenna array may be performed. Operation S160' may include operation S162 and operation S164, and in an exemplary embodiment, each of operation S162 and operation S164 may be performed again based on the result of performing another operation. Hereinafter, FIG19 is described with reference to FIG14.

An operation S162 of determining the spacing of the single elements based on the target beamforming or beamforming standard and/or the gain D160 may be performed. As described above with reference to FIG. 12 , FIG. 13A , FIG. 13B , and FIG. 13C , the gain and HPBW of the antenna module 140 of FIG. 14 may vary according to the spacing of the single elements (i.e., the second spacing P2). Therefore, the spacing of the plurality of single elements may be determined based on the target beamforming and/or the gain D160 of the antenna module 140.

An operation S164 of determining the thickness of the molded portion MO based on the target beamforming and/or gain D160 may be performed. As described above with reference to FIGS. 14 , 15A, and 15B, when the EMC material has a dielectric constant different from that of the dielectric surrounding the end-fire antenna, the active S-parameter and the radiation pattern of the end-fire antenna may vary according to the thickness of the molded portion MO including the EMC material located below the end-fire antenna portion EA. Therefore, the thickness of the molded portion MO located below the end-fire antenna portion EA may be determined based on the target beamforming and/or gain D160 of the antenna module 140.

Although exemplary embodiments have been described with reference to the accompanying drawings, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the appended claims.

10, 10a, 10b, 60, 120, 140, 150a, 150b: antenna module 11, 11a, 11b, 61, G1, G2: block antenna 11_1, 11_1a, 11_1b: first radiator 11_2, 11_2a, 11_2b: second radiator 11_3: third radiator 12, 12a, 12b, 62: ground plane 13, 13a, 13b, 63, 125: electromagnetic bandgap structure 13_1, 13_1a: guide post 62': first additional ground plane 62": second additional ground plane 64, 100, EA1, EA2, EA3, EA4: end-fire antenna 64_1, 100_1: first pattern 64_2, 100_2: second pattern 65: through hole wall 80: pattern 81: first end 82: second end 121: first single element 122: second single element 123: third single element 124: fourth single element A: area D: overlap distance D120: target impedance D142: target main frequency D160: beamforming and/or gain EA, EA', EA'': end-fire antenna part FP1: first feed point FP2: second feed point H1: first distance H2: second distance L1, L2, L3, L4, L5, L6, L7, L8, L9, L10: conductive layer LEAF: leaf part LEN1: first length LEN2: second length MO, MO', MO'': molding part P1: first spacing P2: second spacing PA, PA', PA'': block antenna part PA1: first block antenna PA2: second block antenna PA3: third block antenna PA4: fourth block antenna PI1a, PI1b: first guide post PI2a, PI2b: second guide post PL1a, PL1b: first board PL2a, PL2b: second board PL3a, PL3b: third board PL4a, PL4b: fourth board R1: first area R2: second area S100: design method S120, S120', S122, S124, S140, S140', S142, S144, S160, S160', S162, S164: operation STEM: guide rod part T1a, T1b: first thickness T2a, T2b: second thickness V1a, V1b, V31, V61: first through hole V2a, V2b, V32, V62: second through hole V3a, V3b: third through hole V4a, V4b: fourth through hole V5b: fifth through hole V60: through hole V6b: sixth through hole VP1: first through hole pad VP2: second through hole pad W: width X, Y, Z: axis

The above and other aspects and features can be more clearly understood according to the following detailed description in conjunction with the accompanying drawings, in which: FIG. 1 is a perspective view of an antenna module according to an exemplary embodiment; FIG. 2A and FIG. 2B are plan views of examples of antenna modules according to exemplary embodiments; FIG. 3 is a side view of an antenna module according to an exemplary embodiment; FIG. 4A and FIG. 4B are side views of a column according to an exemplary embodiment; FIG. 5 is a graph showing characteristics of an antenna module according to an exemplary embodiment; FIG. 6 is a plan view of an antenna module according to an exemplary embodiment; FIG. 7 is a side view of an antenna module according to an exemplary embodiment; FIG. 8 is a plan view of a pattern of an end-fire antenna according to an exemplary embodiment of the present inventive concept; 9A and 9B are graphs showing characteristics of an antenna module according to an exemplary embodiment of the present invention; FIG. 10 is a plan view of an end-fire antenna according to an exemplary embodiment; FIG. 11 shows a graph showing characteristics of an antenna module according to an exemplary embodiment; FIG. 12 is a plan view of an antenna module according to an exemplary embodiment of the present invention; FIG. 13A, FIG. 13B, and FIG. 13C are graphs showing characteristics of an antenna module according to an exemplary embodiment; FIG. 14 is a perspective view of an antenna module according to an exemplary embodiment; FIG. 15A and FIG. 15B are side views of an example of an antenna module according to an exemplary embodiment; FIG. 16 is a flow chart of a design method for an antenna according to an exemplary embodiment; FIG. 17 is a flow chart of a design method for an antenna according to an exemplary embodiment; FIG. 18 is a flow chart of a design method of an antenna according to an exemplary embodiment; FIG. 19 is a flow chart of a design method of an antenna according to an exemplary embodiment.

140: Antenna module

EA: End-fire antenna part

MO: Molded part

PA: Block antenna part

X, Y, Z: axis

Claims (19)

An antenna module includes a plurality of conductive layers stacked in a first direction, the antenna module includes: an end-fire antenna, including a first pattern and a second pattern having mutually symmetrical shapes, the first pattern and the second pattern being configured to receive a differential signal fed in a second direction, a through-hole wall, including a plurality of through-holes spaced from the first pattern and the second pattern in the second direction, the plurality of through-holes being configured to receive a ground potential and aligned in a third direction perpendicular to the first direction and the second direction, wherein the first pattern and the second pattern are respectively arranged in different conductive layers and respectively include overlapping portions in the first direction. The antenna module as described in claim 1, wherein each of the first pattern and the second pattern comprises: a rod portion including a first end configured to receive a differential signal, the rod portion extending in the second direction; and a leaf portion connected to the second end of the rod portion, the leaf portion including a shape extending in the second direction away from the second end of the rod portion. An antenna module as described in claim 2, wherein the rod portion of the first pattern at least partially overlaps with the second pattern in the first direction, and wherein the rod portion of the second pattern at least partially overlaps with the first pattern in the first direction. An antenna module as described in claim 2, wherein the leaf portion of the first pattern at least partially overlaps with the second pattern in the first direction, and wherein the leaf portion of the second pattern at least partially overlaps with the first pattern in the first direction. The antenna module as described in claim 1 further comprises: a block antenna, comprising at least one radiator disposed in at least one conductive layer, the block antenna being adjacent to the end-fire antenna; and an electromagnetic bandgap structure, comprising a plurality of columns spaced apart from the at least one radiator in a direction perpendicular to the first direction, the plurality of columns surrounding the at least one radiator. An antenna module as described in claim 5, wherein each of the plurality of pillars comprises two or more plates arranged parallel to each other in two or more conductive layers, and at least one through hole connecting the two or more plates. An antenna module as described in claim 5, wherein the first pattern and the second pattern are respectively arranged in a conductive layer different from the at least one conductive layer in which the at least one radiator is arranged. The antenna module as described in claim 5 further includes: A molding portion including an epoxy molding compound, wherein the molding portion is disposed below the block antenna and the end-fire antenna. An antenna module includes a plurality of conductive layers stacked in a first direction, the antenna module includes: An end-fire antenna including a first pattern and a second pattern having mutually symmetrical shapes, wherein the first pattern and the second pattern are configured to receive a differential signal fed in a second direction, wherein each of the first pattern and the second pattern includes: A rod portion including a first end configured to receive a differential signal, the rod portion extending in the second direction; and A leaf portion connected to the second end of the rod portion, the leaf portion including a shape extending in the second direction away from the second end of the rod portion. An antenna module as described in claim 9, wherein the rod portion of the first pattern at least partially overlaps with the second pattern in the first direction, and wherein the rod portion of the second pattern at least partially overlaps with the first pattern in the first direction. An antenna module as described in claim 9, wherein the leaf portion of the first pattern at least partially overlaps with the second pattern in the first direction, and wherein the leaf portion of the second pattern at least partially overlaps with the first pattern in the first direction. The antenna module as described in claim 9 further includes: A through-hole wall, including a plurality of through-holes separated from the first pattern and the second pattern in the second direction, and arranged in a third direction perpendicular to the first direction and the second direction, respectively, and the plurality of through-holes are configured to receive a ground potential. The antenna module as described in claim 9 further comprises: a block antenna, comprising at least one radiator disposed in at least one conductive layer, the block antenna being adjacent to the end-fire antenna; and an electromagnetic bandgap structure, comprising a plurality of columns spaced apart from the at least one radiator in a direction perpendicular to the first direction, the plurality of columns surrounding the at least one radiator. An antenna module as described in claim 13, wherein each of the plurality of pillars includes two or more plates arranged parallel to each other in two or more conductive layers, and at least one through hole connecting the two or more plates. An antenna module as described in claim 13, wherein the first pattern and the second pattern are respectively arranged in a conductive layer different from the at least one conductive layer in which the at least one radiator is arranged. The antenna module as described in claim 13 further includes: A molding portion including an epoxy molding compound, wherein the molding portion is disposed below the block antenna and the end-fire antenna. An antenna module includes a plurality of conductive layers stacked in a first direction, the antenna module includes: A first end-fire antenna, including a first pattern and a second pattern having mutually symmetrical shapes, wherein the first pattern and the second pattern are configured to receive a differential signal fed in a second direction; A first block antenna, including at least one radiator disposed in at least one conductive layer, and the first block antenna is adjacent to the first end-fire antenna; and An electromagnetic bandgap structure, including a plurality of columns spaced apart from the at least one radiator in a direction perpendicular to the first direction, the plurality of columns surrounding the at least one radiator, wherein the first pattern and the second pattern are respectively disposed in a conductive layer different from the at least one conductive layer in which the at least one radiator is disposed. The antenna module as described in claim 17 further includes: A second block antenna having the same structure as the first block antenna, the second block antenna being spaced apart from the first block antenna in a third direction perpendicular to the first direction and the second direction, wherein the electromagnetic bandgap structure further includes a plurality of columns spaced apart from the second block antenna in the direction perpendicular to the first direction, the plurality of columns at least partially surrounding the second block antenna. The antenna module as described in claim 18 further includes: A second end-fire antenna having the same structure as the first end-fire antenna, the second end-fire antenna being arranged to be adjacent to the electromagnetic bandgap structure in the second direction and spaced apart from the first end-fire antenna in the third direction.